Adult skeletal muscle has its own stem cells, called satellite cells which are responsible for generating new muscle in pathological and physiological condition. These muscles have regeneration potency but their power is not infinite (Non-patent Document 1). There are many incurable skeletal muscle diseases like skeletal muscle dystrophy, myopathy, severe injury, and disuse syndrome (Non-patent Document 2). So it should be extremely useful to elucidate the mechanism of skeletal muscle regeneration and develop a novel regeneration therapy using it. Skeletal muscle development and regeneration are precisely regulated by many various growth factors and cytokines but the regeneration of skeletal muscle cells is not well controllable (Non-patent Document 3). The present inventors previously screened humoral factors and receptors during the cardiomyocyte differentiation of embryonic stem (ES) cells (Non-patent Document 4).
The granulocyte colony stimulating factor (G-CSF) was initially identified as a hematopoietic cytokine and has been used for the mobilization of hematopoietic stem cells in clinics (Non-patent Documents 5, 6, and 7). In addition, G-CSF has various roles in cell differentiation, proliferation and survival (Non-patent document 8).
It was also reported that G-CSF had an action for proliferating muscle cells of rats undergoing skeletal muscle injury so as to enhance the muscle recovery (Non-patent Document 9). However, if G-CSF is involved in the regeneration of skeletal muscle, there are no reports about the underlying mechanism and about the appropriate method, frequency and dosage of actual administration of G-CSF as a muscle repair promoter.
The following is the prior art reference information relevant to the invention of the subject application.